1. Field of the Invention
The present invention relates to a liquid crystal display device (LCD), and more particularly, to a multi-domain liquid crystal display device having a color filter layer with a window distorting electric field and a pixel electrode with a window inducing electric field and method of manufacturing thereof.
2. Description of the Related Art
Recently, a LCD has been proposed where the liquid crystal is not aligned, and the liquid crystals are driven by side electrodes insulated from pixel electrodes. FIG. 1 is a sectional view of a pixel unit of conventional LCDS.
In the conventional LCD, a plurality of gate bus lines arranged in a first direction on a first substrate and a plurality of data bus lines arranged in a second direction on the first substrate divide the first substrate into a plurality of pixel regions. A thin film transistor (TFT) applies an image signal delivered from the data bus line to a pixel electrode 13 on a passivation layer 37. The TFT is formed on each pixel region and comprises a gate electrode, a gate insulator, a semiconductor layer, a source electrode, a drain electrode, etc.
The passivation layer 37 is preferably formed over the whole first substrate. The pixel electrode 13 is coupled to the drain electrode on the passivation layer 37. Side electrode 15 is formed in a region except a region where pixel electrode 13 is formed on the passivation layer 37.
On the second substrate, a light shielding layer 25 is formed shielding light leakage from the gate bus line, data bus line, and TFT. A color filter layer 23 is on light shielding layer 25. A common electrode 17 is on color filter layer 23. A liquid crystal layer is between the first and second substrates.
In addition, an over coat layer 66 may be formed on the color filter layer 23, the over coat layer 66 includes generally organic materials.
A side electrode 15 and an open area 27 of the common electrode 17 distort the electric field applied to the liquid crystal layer. Then, in a unit pixel, liquid crystal molecules are variously driven. This means that when voltage is applied to the LCD, dielectric energy due to the distorted electric field arranges the liquid crystal directors in a needed or desired position.
However, to obtain a multi-domain effect, open area 27 in common electrode 17 is necessary, which requires patterning of the common electrode 17. Moreover, if the electrodes do not have an open area or the width thereof is narrow, the distortion of electric field needed to divide the pixel region becomes weak. Then, when voltage over a threshold voltage, Vth, is applied, the time needed the liquid crystal directors to become stable increases.
Moreover, in the process of depositing and patterning the common electrode, since the common electrode 17 is formed directly on the color filter layer 23 or on the over coat layer 66, the tackiness of the electrode decreases and then the uniformity of the open area decreases.
Accordingly, the present invention is directed to a liquid crystal display device that substantially obviates one or more problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a multi-domain LCD having a color filter layer with a window distorting electric field and a pixel electrode with a window inducing electric field and method of manufacturing thereof.
Another object of the present invention is to provide an organic or inorganic layer on the color filter layer so that it increases the tackiness of the electrode and the precision of the pattern.
A further object of the present invention is to provide a LCD having a wide viewing angle resulting from a multi-domain effect.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve the objects and in accordance with the purpose of the invention, as embodied and broadly described herein, a multi-domain liquid crystal display device comprises includes first and second substrates facing each other; a liquid crystal layer between the first and second substrates; a plurality of gate bus lines arranged in a first direction on the first substrate and a plurality of data bus lines arranged in a second direction on the first substrate to define a pixel region; a thin film transistor positioned at a crossing area of the data bus line and the gate bus line, the thin film transistor comprising a gate electrode, a semiconductor layer, and source/drain electrodes; a pixel electrode on the first substrate, the pixel electrode having at least one window inducing electric field therein; a color filter layer on the second substrate, the color filter layer having at least one window distorting electric field therein; a common electrode on the color filter layer; and an alignment layer on at least one substrate between the first and second substrates.
In another aspect of the present invention, a method of manufacturing a multi-domain liquid crystal display device comprises the steps of providing first and second substrates facing each other; forming a pixel electrode on the first substrate, the pixel electrode having at least one window inducing electric field therein; forming a color filter layer on the second substrate, the color filter layer having at least one window distorting electric field therein; and forming a common electrode on the color filter layer.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.